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Cosmology and the Origin of the Universe:

Historical and Conceptual Perspectives

Helge Kragh*

Abstract: From a modern perspective cosmology is a historical science in so far

that it deals with the development of the universe since its origin some 14

billion years ago. The origin itself may not be subject to scientific analysis and

explanation. Nonetheless, there are theories that claim to explain the ultimate

origin or “creation” of the universe. As shown by the history of cosmological

thought, the very concept of “origin” is problematic and can be understood in

different ways. While it is normally understood as a temporal concept, cosmic

origin is not temporal by necessity. The universe can be assigned an origin

even though it has no definite age. In order to clarify the question a view of

earlier ideas will be helpful, these ideas coming not only from astronomy but

also from philosophy and theology.

1. Introduction: concepts of origin

In a lecture of 1993 the famous British astrophysicist and cosmologist, Fred Hoyle,

recommended that “Whenever the word ‘origin’ is used, disbelieve everything you

are told.” He added, “The biggest pig in a poke where origins are concerned is that of

the whole universe.”1 Whatever the opinion of Hoyle the concept of origin is

generally difficult and often tricky, for other reasons because the term is used in

different contexts and with different meanings. According to the Oxford English

Dictionary, origin means “the act or fact of beginning, or of springing from

something; beginning of existence with reference to source or cause; rise or first

* Niels Bohr Institute, University of Copenhagen, Denmark. E-mail: helge.kragh@nbi.ku.dk.

This paper is an English version of a chapter to be published later in 2017 in a book in

Spanish, titled Orígenes and edited by Ángel Díaz de Rada at the Open University in Spain

(UNED). 1 Fred Hoyle, The Origin of the Universe and the Origin of Religion (London: Moyer Bell, 1993),

p. 18.

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manifestation.”2 Several other, more or less synonymous words are in use, such as

start, genesis (or generation), birth, dawning, emergence, and creation. However, in

reality the words cover a wide spectrum of meanings and are thus not proper

synonyms.

Typically, when we ask “what is the origin of X” we inquire about how X was

once formed or came into being. A satisfactory answer is supposed to relate to certain

states of the past from which X emerged. When we say that a person’s country of

origin is Algeria we mean that he or she was born and raised in Algeria. As a more

relevant example, consider the origin of the Earth, a question which for long was a

puzzle to geologists and astronomers but is now well (if not completely) understood.

According to the consensus theory the Earth was formed approximately 4.5 billion

years ago from gravitationally caused accretion of matter particles in the solar

nebula. If this theory turns out to be correct we will have scientifically valid

knowledge concerning the origin of the Earth. In some cases the origin of X is

something which happened almost momentarily but in other cases it is a slow and

gradual process to which no definite time in the past can be assigned. Given that the

Earth’s crust solidified 4.54 0.05 billion years ago, the origin of the Earth took place

quickly, at least on a geological time scale.

The case of the origin of the biological species, as first fully addressed in

Charles Darwin’s famous The Origin of Species from 1859, is in this regard quite

different. Zoologists can explain how and approximately when the mammoth

evolved from earlier elephants, but in this and some other cases origin means

essentially evolution. Indeed, to account for the origin of X often means to come up

with a history of how X developed from ancestral forms. The two cases have in

common that there was a time when X did not exist. For 6 billion years ago there was

no Earth, and for 10 million years ago there were no mammoths. We will not

normally wonder about the origin of something which has always existed and to

which a first instance cannot be ascribed (but see Section 2). Likewise, we will not

normally wonder about the origin of something which has never existed – we may be

interested in the origin of the belief in unicorns but not in the origin of unicorns.

In many cases X refers to an object or a class of objects, but it may also be a

phenomenon. What is the origin of the enigmatic colours of the aurora borealis? In

this case scientists will point to mechanisms in the atoms in the upper strata of the

2 http://www.oed.com (accessed 10/08/2026).

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atmosphere, at a height of approximately 100 km, which are responsible for the

wavelengths identified in the spectrum of the aurora. Similarly, to explain the origin

of the present phenomenon of global warming they will examine models of how

solar heat behaves in an atmosphere containing carbon dioxide and other greenhouse

gases. In none of these cases does the concept of origin have a direct temporal

meaning as it primarily relates to a causal mechanism. Nonetheless, since the

phenomena are effects of certain causes, and causes always precede the effects, there

is implicitly a temporal link.

When we consider the so-called origin of the universe, things become much

more difficult. In the mentioned examples the origin of X is taken to refer to either an

ancestral state or something from which the existence of X can be derived either

causally or in some other way. Consider a radioactive decay where a certain atom Y

transmutes into another atom X; since the X atom did not exist before the decay we

may say that it was created. The decay process is governed by the probabilistic laws

of quantum mechanics which means that no cause can be given why X was created at

a definite time. Nevertheless, although a sufficient cause cannot be given, the decay

depends on necessary causes. For example, if there were no atoms of type Y the

creation of X would not happen. It depends on a prior state, which distinguishes it

from the case of the creation or origin of the big bang universe.

In most cases it makes sense to say that Y was the cause of X; by specifying Y

we can account for the origin of X but only by making the perhaps obvious

assumption that Y and X are parts of the universe. Given the standard definition of

the universe we cannot speak in the same manner if X = universe. It is of crucial

importance to be aware that the two statements “the Earth is 4.5 billion years ago”

and “the universe is 13.7 billion years ago” are entirely different. If the universe has

an absolute origin it presumably means that it came into being as a result of

something either before or outside the universe. None of the options seem to make

much sense from a scientific point of view and perhaps not even from a logical point

of view. Sometimes the question of the origin of life is considered to be of a status

similar to the one of the origin of the universe. But this is a mistake, I think. Although

we do not know the answer to the first question it can presumably be answered in

the traditional way, that is, to find out when and how primitive life forms first

evolved from complex organic but abiotic molecules.

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To discuss the question of the origin of the universe in either an evolutionary or

an absolute version I shall adopt a historical approach.3 Despite the enormous

progress cosmology has made during the last century the origin problem has not

come substantially closer to a solution. From a philosophical rather than scientific

perspective it was much discussed during the previous centuries, and some of the

arguments entering the discussions are still worth to recall. Precisely because they

were not limited to a modern scientific perspective they sometimes included

viewpoints concerning the origin of the universe of conceptual originality and

interest.

2. Ancient and medieval periods

The question of the origin of the universe has not always constituted a significant

part of cosmological thought. Although there have been periods in which it was

considered important, such as is obviously the case today, through most of history

the question failed to attract much attention or was even considered outside the

scientific study of the cosmos. Yet the very earliest concerns with the heavens were in

the form of cosmogonies rather than cosmologies, meaning that they were attempts to

understand how the present world or universe had come into existence. According to

the cosmogonies of the ancient Egyptian and Mesopotamian civilizations, the

universe was created as a dynamic entity which gave rise to everything existing,

including humans and gods.4 The stories that the learned ancients told about the

origin and evolution of the universe were not scientific but mythological. Because of

the crucial role played by the gods the stories were theogonies as much as they were

cosmogonies. The two genres were indistinguishable.

A common feature to be found in both of the great river cultures was the belief

that the creative process started with an undifferentiated watery chaos which the

gods subsequently separated into two or more separate realms, thereby creating

Earth and the heaven as distinct bodies. The original state of darkness and lifeless

3 Modern histories of cosmology dealing with the subject from the oldest time to the present

include John North, Cosmos: An Illustrated History of Astronomy and Cosmology (Chicago:

University of Chicago Press, 2008) and Helge Kragh, Conceptions of Cosmos. From Myths to the

Accelerating Universe: A History of Cosmology (Oxford: Oxford University Press, 2007). 4 See, for example, Carmen Blacker and Michael Loewe, eds., Ancient Cosmologies (London:

George Allen & Unwin, 1975) and chapters in Norriss S. Hetherington, ed., Encyclopedia of

Cosmology: Historical, Philosophical, and Scientific Foundations of Modern Cosmology (New York:

Garland Publishing, 1993).

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uniformity was posited but not explained. In any case, the primary concern of the

early cosmogonies was not to describe the universe but to account for the existence of

its inhabitants in the form of gods, humans and everything else. This is the kind of

story we meet in the Mesopotamian creation myth Enuma Elish, dating from about

1500 BC, and also in the much later Theogony written by the Greek poet Hesiod. A

different variant of the creation theme appears in the Jewish cosmogony as described

in the very beginning of Genesis:

In the beginning, when God created the universe, the Earth was formless and desolate.

“Let there be light – and light appeared.” … Then He separated the light from the

darkness … Then God commanded, “Let the water below the sky come together in one

place, so that the land will appear” – and it was done. He named the land “Earth” and

the water which had come together he named “Sea.”

The crucial novelty, apart from the introduction of a single almighty and non-created

God, is the absence of a primordial state. So, from what did God create the universe?

The text does not say that he created it out of nothingness, but in later Christianity it

became a dogma that this is what happened. First there was nothing and then,

because God wanted it, there was something. Creatio ex nihilo.5 As early as the fifth

century AD the church father St. Augustine pointed out that God’s creation of the

world included time itself. “The world was made, not in time, but simultaneously

with time,” he wrote.6 There was no time before the universe.

With the rise of Greek natural philosophy and its gradual transformation

into science, astronomy emerged as a mathematical discipline focused on

observations of the planetary system; on the other hand, speculations about the

origin of the world declined drastically.7 In the long period between Plato and

5 God’s creation of the world ex nihilo dates from the second century but was only made an

official doctrine of the Catholic Church at the Fourth Lateran Council in 1215. Experts

disagree of whether or not the idea is implied by Genesis or other parts of the Bible. For

opposing views, see Gerhard May, Creatio ex Nihilo: The Doctrine of “Creation Out of Nothing”

in Early Christian Thought (Edinburgh: T & T Clark, 1994) and Paul Copan and William L.

Craig, Creation Out of Nothing: A Biblical, Philosophical, and Scientific Exploration (Grand

Rapids: Baker Academic, 2004). 6 Vernon Bourke, ed., The Essential Augustine (Indianapolis: Hackett Publishing Company,

1974), p. 109. 7 On aspects of Greek cosmological thought, see Samuel Sambursky, The Physical World of the

Greeks (London: Routledge, 1963), Richard D. McKirahan, Philosophy Before Socrates

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Ptolemy cosmogony, in the strict meaning of the term, practically came to a halt.

However, questions concerning the origin of the world and its subsequent evolution

continued being addressed by natural philosophers outside the mainstream

Aristotelian tradition. One of them was the Roman poet Titus Lucretius Carus, an

advocate of the much earlier atomistic philosophy going back to Democritus and

Epicurus.

In a famous text composed about 50 BC called De Rerum Natura (On the

Nature of Things), Lucretius described the atomists’ infinite universe solely made up

of atoms in incessant motion. This universe was of finite age and “there will be an

end to the heaven and the Earth.”8 Rather than basing his argument on some

mythological scenario Lucretius called attention to the shortness of human history.

Apparently unable to conceive a world without humans (or without poets), he asked:

“If there was no origin of the heavens and Earth from generation, and if they existed

from all eternity, how is it that other poets, before the time of the Theban war, and

the destruction of Troy, have not also sung of other exploits of the inhabitants of

Earth?” Lucretius suggested that “the whole of the world is of comparatively modern

date, and recent in its origin.” He and a few other philosophers of the atomistic and

Stoic schools argued that “The walls of the great world, being assailed around, shall

suffer decay, and fall into mouldering ruins.” From this they concluded that the

world cannot be eternal in the past but must have had a beginning in time.9

The philosophical cosmology of Lucretius, including its associated

cosmogony, differed completely from the far more influential ideas of Aristotle

expounded in his De Caelo (On the Heavens) and other works. Aristotle’s cosmos was

in a steady state in so far that it was eternal, and local non-circular changes were

restricted to the sublunary world. He argued that the universe as a whole, apart from

being unique (no other universes), was spatially finite but temporally infinite in both

(Indianapolis: Hackett Publishing Company, 1994), and M. R. Wright, Cosmology in Antiquity

(London: Routledge, 1995). 8 Lucretius, On the Nature of Things (Amherst, NY: Prometheus Books, 1997), quotations from

pp. 45-46, 93, and 205. 9 Versions of this kind of argument against the eternity of the world can be found much

earlier. The Stoic philosopher Zeno of Citium developed it on the basis of the observed

erosion processes on the Earth’s surface. See Gad Freudenthal, “Chemical foundations for

cosmological ideas: Ibn Sina on the geology of an eternal world,” pp. 47-73 in Sabetai

Unguru, ed., Physics, Cosmology and Astronomy 1300-1700: Tensions and Accommodation

(Dordrecht: Kluwer, 1991).

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directions. In other words, it was eternal and hence uncreated as well as

indestructible.

Suppose, Aristotle said in De Caelo, that the world was formed out of some

pre-existing and unchanging elements. “Then if their condition was always so … the

world could never have come into being. And if the world did come into being, then,

clearly, their condition must have been capable of change and not eternal.”10 He

further referred to what in cosmological thought is known as the “why not sooner?”

argument, namely: If the universe came into being a finite time ago, what reason

could there possibly be for just this time rather than some other time? In the words of

Aristotle: “Why, after an infinity of not being, was it generated, at one moment rather

than another? If there is no reason and the moments are infinite in number, it is clear

that a generated or destructible thing existed for an infinite time.” Augustine would

later counter that the universe could not possibly have come into existence at an

earlier time since there was no time before the universe began.11 Aristotle

summarized his position as follows: “The heaven as a whole neither came into being

nor admits of destruction, … but is one and eternal, with no end or beginning.”

Aristotle’s assumptions about a finite and eternal cosmos were not generally

accepted in the Greek-Roman culture, but later they came to dominate the medieval

world view. There was one exception though, namely the controversial and most un-

Christian claim of the universe being past eternal.

The Christian universe was divinely created out of nothing and hence of

finite age, in sharp contradiction to what Aristotle had taught. As early as the sixth

century the Christian philosopher Johannes Philoponus developed a series of rational

arguments based on the concept of infinity against Aristotle’s heresy. Let us assume,

Philoponus said, that the world had always existed and been populated with

humans. In that case, there would have existed an infinity of humans up to the time

of Socrates. But, he went on, “there will have to be added to it the individuals who

came into existence between Socrates and the present, so there will be something

10 Quotations from Jonathan Barnes, ed., The Complete Works of Aristotle, vol. 1 (Princeton:

Princeton University Press, 1984), pp. 461-470. 11 The “why not sooner?” argument against a cosmic beginning can be found in the pre-

Socratic philosopher Parmenides and was later discussed by Leibniz and Kant. See Brian

Leftow, “Why didn’t God create the world sooner?” Religious Studies 27 (1991), 157-172.

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greater than infinity, which is impossible.”12 Another variant of his argument related

to the periods of revolution of the planets and stars. If Saturn had revolved infinitely

many times, Jupiter would have performed three times as many revolutions and the

stars many more times as many. This he thought was not only incredible but strictly

impossible. “Thus necessarily the revolution of the heavenly bodies [and hence the

universe itself] must have a beginning.”

Much later, when Aristotle’s philosophical system had been rediscovered

and to a large part incorporated in the medieval-Christian world view, the problem

of cosmic origin remained controversial. It caused the great theologian Thomas of

Aquinas to re-examine the idea of creation. Could God have created an eternal

universe? Creation and eternity may appear to be mutually exclusive concepts, but

Aquinas pointed out that since God is a non-temporal being he did not need to

precede his effects in time. God did not transform “nothing” into something, he

causes things to exist continually in the sense that if they were left to themselves they

would return to nothingness. Aquinas distinguished between a temporal beginning

of the universe and its creation, where the latter concept refers to the existence of the

universe as such. From this point of view an eternal yet created universe was

perfectly possible. Even if the universe had no temporal beginning, it would still

depend upon God’s power for its very being.13 Creation, Aquinas argued in De

Aeternitatis Mundi from about 1270, had a double meaning:

The first is that it presupposes nothing in the thing which is said to be created. … The

second thing is that non-being is prior to being in the thing which is said to be created.

This is not a priority in time or of duration, such as that what did not exist before does

exist later, but a priority of nature, so that, if the created thing is left to itself, it would

not exist, because it only has a being from the causality of the higher cause.

12 For Philoponus’s arguments, see Richard Sorabji, Time, Creation and the Continuum: Theories

in Antiquity and the Early Middle Ages (Chicago: University of Chicago Press, 1983).

Modernized versions of the infinity paradoxes of the Greek thinker have continued to attract

attention. They were used in the 1970s as an argument against the steady-state theory of the

universe. See Gerald Whitrow, “On the impossibility of an infinite past,” British Journal for the

Philosophy of Science 29 (1978), 39-45. 13 See William Carroll, “Thomas Aquinas and big bang cosmology,” Sapientia 53 (1998), 73-

95, from which the quotation is taken. See also Conrad Hyers, The Meaning of Creation:

Genesis and Modern Science (Atlanta: John Knox Press, 1984), and Copan and Craig, Creation

Out of Nothing, pp. 147-157 (ref. 5).

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Bonaventure, a contemporary Franciscan theologian, argued against Aquinas that the

eternity of the world was heretical as well as philosophically absurd; because, had

the world existed in an eternity the number of revolutions in the heavens must have

been infinite, and for this reason the present could never have been reached. But it

was Aquinas and not Bonaventure who won the discussion. Continual but timeless

creation was eventually adopted by the Catholic Church under the name creatio

continua (as opposed to creatio originans).

3. From Kant to Einstein

During the scientific revolution, roughly the 150-year period between Copernicus

and Newton, astronomy was established as a branch of mechanical physics.

Telescopic observations greatly expanded the astronomers’ horizon, but the progress

was basically limited to the solar system. Generally, cosmology played very little role

and cosmogony even less. The question of the origin of the world was largely a non-

question in the sense that everyone agreed that of course the world was divinely

created. Characteristically, when the great astronomers of the period addressed the

issue of the time of creation – and many of them did – they looked to biblical

chronology rather than trying to answer the question by scientific means. Johannes

Kepler found in this way that God had created the universe 3983 BC; the Danish

astronomer Longomontanus, a pupil of Tycho Brahe, arrived at 3967 BC.

Whereas the date of creation could only be inferred from the Bible, a finite-

age universe could be argued without it. If the cosmos were a machine slowly

running down, such as Newton came to believe, it could not have existed forever, for

in that case it would already be in a state of total dissolution (which it is not). As the

British astronomer James Ferguson expressed it in a book of 1757, “For, had it existed

from eternity, and been left by the Deity to be governed by the combined actions of

the above [Newtonian] forces or powers, generally called Laws, it had been at an end

long ago.”14 It was neither the first nor the last time that a counterfactual argument of

this kind was used as evidence for a universe of finite age. As mentioned, it can be

found much earlier in Lucretius’ De Rerum Natura and other of the sources of ancient

natural philosophy.

14 Quoted in Helge Kragh, Entropic Creation: Religious Contexts of Thermodynamics and

Cosmology (Aldershot: Ashgate Publishing, 2008), p. 19, where other examples of the

argument can be found.

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The traditional view was that God had created the universe more or less as it

still is, but during the era of the Enlightenment this view was challenged by a series

of evolutionary cosmogonies. According to these scenarios, the world as presently

observed was the outcome of a slow evolutionary process starting in a very different

state, perhaps a primordial chaos of the kind that the ancient atomists had assumed.

The most innovative and elaborated version of the evolutionary cosmogonies was

published in 1755 by 31-year-old Immanuel Kant as Allgemeine Naturgeschichte und

Theorie des Himmels (Universal History and Theory of the Heavens). Kant started with

a primeval, divinely created chaos of particles and then, ostensibly relying on the

principles of Newtonian mechanics, explained how the chaotic state naturally

evolved into condensations out of which the solar system and indeed the whole

ordered universe was formed. What matters in the present context is that Kant’s

cosmic creation was an evolutionary process allegedly governed by the laws of

physics and thus quite different from creation once and for all. “Creation is not the

work of a moment,” he emphasized. “Creation is never completed. Though it has

once started, it will never cease. It is always busy in bringing forth more scenes of

nature, new things and new worlds.”15

While young Kant optimistically believed that the universe as a whole would

be subject to scientific analysis, apparently he changed his mind. In his far better

known and more influential Kritik der reinen Vernunft (Critique of Pure Reason) of

1781 he concluded that the notions of age and extent were meaningless when applied

to the universe. In his so-called first antimony he first proved by means of logical

arguments that “The world has a beginning in time, and is limited also with regard

to space;” he next proved the opposite, that is, “The world has no beginning and no

limits in space, but is infinite, in respect both to time and space.”16 Since the concept

of the world at large was thus contradictory, he concluded that it cannot cover a

physical reality but only be a concept of heuristic value. It was what he called a

regulative principle. Kant’s cosmogony of 1755 became the backbone of the later

nebular hypothesis, also known as the Kant-Laplace hypothesis, which played a very

important role during the nineteenth century. The role was controversial as well, for

the hypothesis of a nebular origin of the universe, with no explanation of the original

15 Immanuel Kant, Universal Natural History and Theory of the Heavens, translated and edited

by Stanley L. Jaki (Edinburgh: Scottish Academic Press, 1981), p. 155. 16 Critique of Pure Reason, Chapter II, Section II.

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nebular stuff, was sometimes taken to imply an eternal and uncreated universe.17

Evolution did not square easily with creation.

In 1858 the German astronomer Johann Mädler suggested an argument for

the origin of the universe a finite time ago which relied on observation rather than

logic. His aim was not so much to provide evidence for a created universe, which he

took for granted, as it was to explain the so-called Olbers’ paradox of the darkness of

the sky at night. The name refers to another German astronomer, Heinrich Wilhelm

Olbers. As had been pointed out as early as the seventeenth century, if the universe

was infinitely (or just enormously) large and filled uniformly with stars, the

accumulated starlight should make the sky at night as bright as on a sunny day. And

yet the night is dark. Mädler’s solution was to combine the finite velocity of light

with the hypothesis that the stars had not always existed. “If we knew the moment of

creation, we should be able to calculate its boundary,” he wrote, referring to the stars

most far away.18 However, his suggestion attracted almost no attention and was only

revived much later in connection with the expanding universe discovered around

1930.

As mentioned, the question of the origin of the universe was given little

priority by the astronomers. But it was considered interesting by the philosophers

who in the spirit of Kant analysed it from a logical and conceptual point of view. One

of them was Herbert Spencer, a prominent evolutionary philosopher in favour of the

nebular world view. Spencer distinguished between three assumptions concerning

the origin of the universe in an absolute sense. We may assert, he wrote in First

Principles first published in 1862, that the universe is self-existent, or that it is self-

created, or that it is created by an external agency. His analysis of the three

possibilities led him to a conclusion no less pessimistic than the one Kant had arrived

at more than eighty years earlier:

17 Stephen G. Brush, “The nebular hypothesis and the evolutionary worldview,” History of

Science 25 (1987), 245-278; Ronald L. Numbers, Creation by Natural Law: Laplace’s Nebular

Hypothesis in American Thought (Seattle: University of Washington Press, 1977). 18 Johann Mädler, Der Fixsternhimmel (Leipzig: Brockhaus, 1858), as quoted in Frank J. Tipler,

“Johann Mädler’s resolution of Olbers’ ‘paradox´,” Quarterly Journal of the Royal Astronomical

Society 29 (1988), 313-325. For the complex history of Olbers’ paradox, see Stanley L. Jaki, The

Paradox of Olbers’ Paradox (New York: Herder and Herder, 1969) and Edward Harrison,

Darkness at Night: A Riddle of the Universe (Cambridge, MA: Harvard University Press, 1987).

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Thus these three different suppositions respecting the origin of things, verbally

intelligible though they are, and severally seeming to their respective adherents quite

rational, turn out, when critically examined, to be literally unthinkable. It is not a

question of probability, or credibility, but of conceivability. … Impossible as it is to

think of the actual universe as self-existing, we do but multiply impossibilities of

thought by every attempt we make to explain its existence.19

Cosmic creation might be beyond human comprehension, but it did not prevent

scientifically based arguments for the universe being of finite age. The discovery in

the 1850s of the second law of thermodynamics implied a tendency of all natural

processes towards an equilibrium state of uniform temperature. If extrapolated to the

far future, it indicated that all activity in the universe would come to an end, a state

known as the “heat death.” If extrapolated to the far past, it indicated that the

universe had a beginning in time – or rather that there was a beginning for the

operation of the laws of nature. The argument was often stated in terms of Rudolf

Clausius’ concept of entropy, a quantity which is a measure of degradation and has

the unique property that it always increases in a closed system. The “entropic

creation argument” can be stated counterfactually: if the universe had existed in an

eternity of time, the entropy must now have reached its maximum; but since there is

order and structure in the universe, this is obviously not the case; it follows that the

age of the universe is finite, meaning that it had a beginning.20

This kind of argument, often supplied with the apologetic assumption that

cosmic beginning implied divine creation, was hotly debated from about 1865 to

1915, but more among philosophers and theologians than among astronomers. It did

not succeed in making a universe of finite age generally accepted. As late as 1913 the

eminent British geophysicist Arthur Holmes referred to the entropic creation

argument as follows:

If the development of the universe be everywhere towards equalization of temperature

implied by the laws of thermodynamics, the question arises – why in the abundance of

time past, has this melancholy state not already overtaken us? Either we must believe

in a definite beginning, in the creation of a universe furiously ablaze with energy, or

19 Herbert Spencer, First Principles (New York: P. F. Collier & Son, 1902), pp. 49-50. 20 See Kragh, Entropic Creation (ref. 14) for a full account of the argument and its history.

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else we must assume that the phenomena we have studied simply reflect our limited

experience.21

However, Holmes denied the validity of the argument and maintained that the

universe as a whole had existed eternally and probably evolved through an infinite

number of cycles.

At the time of World War I cosmology did not yet exist as a scientific

discipline. In so far that astronomers dealt with cosmological questions they focused

on the structure of the stellar universe, in particular the size of the Milky Way and its

relation to the nebulae. Were the nebulae parts of the Milky Way system or were they

huge conglomerates of stars, milky ways in their own right, far away from it?

In 1917 Albert Einstein laid the foundation of modern cosmology by

proposing a model of the universe on the basis of his new theory of gravitation, the

general theory of relativity.22 Although Einstein’s model was a revolution in

cosmological thought, its picture of the universe was in some sense traditional. The

model presupposed that the universe as a whole was uniform and spatially closed

corresponding to a positive curvature of space; it was finite yet with no boundary

and therefore contained but a finite number of stars. Importantly, it was also static in

the sense that the curvature of space and the mean density of matter remained

constant. To maintain a static universe in accordance with astronomical observations

Einstein had to introduce a new term in his cosmological field equations, the later so

famous cosmological constant. Being static his universe had no temporal dimension

but was eternal in both past and future time. For this reason alone the question of the

origin of the universe did not enter Einstein’s mind. Nor did it enter the minds of the

few other physicists and astronomers occupying themselves with his mathematically

and conceptually abstruse theory.

4. The big bang hypothesis

It turned out that Einstein’s cosmological field equations were much richer in

mathematical structure than he thought at first. The equations do not merely describe

a static universe of the type Einstein examined in 1917 but also a whole class of

21 Arthur Holmes, The Age of the Earth (New York: Harper, 1913) , p. 121 22 Albert Einstein, “Cosmological considerations on the general theory of relativity,” pp. 175-

188 in A. Einstein et al., The Principle of Relativity (New York: Dover Publications, 1952);

Pierre Kerzberg, The Invented Universe: The Einstein-De Sitter Controversy (1916-1917) and the

Rise of Relativistic Cosmology (Oxford: Clarendon Press, 1992).

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dynamical models, that is possible universes with a curvature (and hence size) that

varies in time. The first to point out these mathematical solutions was the Russian

physicist Alexander Friedmann, who in a paper of 1922 analysed all uniform models

described by the field equations. Some of these models were expanding, meaning

that the size of the universe (as given by the distance measure R) increased in cosmic

time t. As Friedmann realized, there were models with the remarkable property that

R = 0 for t = 0 in the past, or what he called a “beginning of the world.” R = 0

corresponds to a point in space, a “singularity” with no spatial extension at all.

Friedmann wrote: “The time since the creation of the world is the time which has

passed from the moment at which space was a point (R = 0) to the present state (R =

R0).”23

Here we have, for the first time, the notion of the origin of the universe

derived not from a philosophical doctrine but from a fundamental theory of physics.

On the other hand, Friedmann’s brilliant investigation was primarily a mathematical

exercise and he did not express any preference for one model over another. He did

not argue that our universe is in fact expanding or that it really had an origin in a

singularity. At any rate, for nearly a decade his paper remained either unknown or

unappreciated.

By 1930 the expansion of the universe, now supported by observation as well

as theory, had become a reality. But the notion of a beginning of the world does not

follow logically from cosmic expansion. What became known as the big bang

universe in a realistic sense was first proposed on 9 May 1931 in a brief note in the

journal Nature. The author was Georges Lemaître, a 36-year-old Belgian

astrophysicist and cosmologist who was also trained as a Catholic priest.

“We could conceive,” Lemaître wrote in his 1931 paper, “the beginning of the

universe in the form of a unique atom, the atomic weight of which is the total mass of

the universe … [and which] would divide in smaller and smaller atoms by a kind of

super-radioactive process.”24 He used the term “atom” in a metaphorical sense close

to that of the ancient Greeks, namely as something completely undifferentiated and

23 Alexander Friedmann, “Über die Krümmung des Raumes,” Zeitschrift für Physik 10 (1922),

377-386; Harry Nussbaumer and Lydia Bieri, Discovering the Expanding Universe (Cambridge:

Cambridge University Press, 2009). 24 G. Lemaître, “The beginning of the world from the point of view of quantum theory,”

Nature 127 (1931), 706. For details and perspectives, see Helge Kragh and Dominique

Lambert, “The context of discovery: Lemaître and the origin of the primeval-atom

hypothesis,” Annals of Science 64 (2007), 445-470.

15

devoid of physical properties. Moreover, he carefully spoke about the beginning or

origin of the universe, not its creation. As a faithful Catholic Lemaître was convinced

that God had created the universe, and yet he stressed that its origin was a natural

event and that his theory was purely scientific. At one occasion he wrote that “the

hypothesis of the primeval atom is the anti-thesis of the supernatural creation of the

world.” He elaborated:

We may speak of this event as of a beginning. I do not say a creation. Physically it is a

beginning in the sense that if something has happened before, it has no observable

influence on the behaviour of our universe. … Any pre-existence of our universe has

a metaphysical character. Physically everything happens as if it was really a

beginning. The question if it was really a beginning or rather a creation, something

starting from nothing, is a philosophical question which cannot be settled by physical

or astronomical considerations.25

According to Lemaître’s scenario, at t = 0 the universe already existed in the shape of

what he called a “primeval atom,” a relatively small body of enormous mass density.

Such a hypothetical super-atom was comprehensible if not subject to scientific

analysis. Lemaître insisted that it was physically meaningless to speak of time before

the initial explosion and yet he wrote, inconsistently it seems, “the beginning of the

world happened a little before the beginning of space and time.” But if time came

into being only with the original explosion (the big bang), how could the world have

begun “a little before”? According to Lemaître, immediately after the disintegration

of the primeval atom it would, at least in principle, be possible to analyse the very

early universe by means of the laws of physics. Whereas he considered the primeval

atom to be real, he denied that the cosmic singularity R = 0 formally turning up in the

equations at t = 0 could be ascribed physical reality. The “annihilation of space,” as

he called it, was for him a mathematical artefact.

Well acquainted with the philosophical classics Lemaître knew about Kant’s

argument against a cosmic beginning. If the universe started with the explosion of

the primeval atom, what caused the explosion? Cause precedes the effect, so how can

there be a causal agent before the beginning when time did not even exist? Lemaître

admitted that Kant’s objection was a genuine dilemma in so far that the universe is

governed by the principles of causality and determinism inherent in classical

25 Quoted in H. Kragh, Matter and Spirit in the Universe: Scientific and Religious Preludes to

Modern Cosmology (London: Imperial College Press, 2004), pp. 147-148.

16

mechanics. But in quantum mechanics processes can occur without a cause, such as

is the case in radioactive decay. Lemaître considered the quantum origin of the

universe to be essential, for only in this way could one avoid the tricky question of

what caused the initial disintegration. Although his idea was received with interest

in the popular press, astronomers either ignored or rejected it. A Canadian

astronomer characterized it as “the wildest speculation of all” and “an example of

speculation run mad.”26 And yet it was out of this wild speculation that the modern

theory of the big bang universe emerged.

In the late 1940s Lemaître’s daring hypothesis was independently

transformed into a more detailed and advanced theory of the early universe, now by

conceiving it in terms of nuclear physics. According to the Russian-American

physicist George Gamow the very early universe was a hot and dense inferno of

interacting nuclear particles, and as a result of the interactions the chemical elements

were formed during a brief period in the cosmic past. Together with his collaborators

Ralph Alpher and Robert Herman he realized in 1948 that the earliest inferno must

consist predominantly of high-energy radiation rather than particles such as protons

and neutrons. On this basis they succeeded in establishing the essential features of

the “hot big bang” theory as it is known today. With respect to the absolute origin of

the universe, Gamow intentionally disregarded it. He and his collaborators simply

started their calculations in a pre-existing original universe, without concerning

themselves with where it came from (except that Gamow speculated that the big

bang might be the result of the collapse of a previous universe – a “big crunch”).

Although his cosmological model was often labelled a creation theory, in reality it

was an evolution theory. Gamow did use the term “creation,” but merely in the

innocent sense of “making something shapely out of shapelessness.”27

Finite-age models of the type proposed by Lemaître and Gamow were

challenged by the fundamentally different steady state theory of the universe

introduced by Fred Hoyle, Hermann Bondi and Thomas Gold in 1948. According to

this theory the universe had existed in an eternity of time and would continue

existing eternally. Moreover, its average density of matter remained the same despite

its continual expansion, which was explained by postulating a tiny amount of matter

26 John S. Plaskett, “The expansion of the universe,” Journal of the Royal Astronomical Society of

Canada 27 (1933), 235-252. 27 G. Gamow, The Creation of the Universe (New York: Viking Press, 1952), preface.

17

creation throughout the universe.28 This element of spontaneous matter creation

aroused heated debate. While some scientists objected that the fundamental law of

energy conservation could not be violated, philosophers tended to conceive matter

creation as an example of deus ex machina reasoning. To Mario Bunge, a physicist and

philosopher, the steady state theory was nothing but “science-fiction cosmology.”29

Of course, Hoyle and his supporters denied the charges.

What matters is that by assuming an infinite age of the universe the steady

state theorists avoided the thorny question of a beginning. It was in this context that

Hoyle, on 28 March 1949, gave a BBC broadcast in which he coined the name “big

bang” for the kind of cosmological theory which assumed an origin of the universe in

an explosive event. The following year he characterized “the big bang assumption

[as] an irrational process that cannot be described in scientific terms.”30 What he had

in mind was the old objection that there can be no causal explanation, indeed no

explanation of any kind, for the beginning of the universe. At more than one occasion

he associated the big bang theory with theism, suggesting that a temporal beginning

of the universe implied divine creation and was therefore unscientific. For example:

“The passionate frenzy with which the big-bang cosmology is clutched to the

corporate scientific bosom evidently arises from a deep-rooted attachment to the first

page of Genesis, religious fundamentalism at its strongest.”31

During the period from 1948 to the early 1960s the steady state theory was a

serious alternative to evolutionary models based on Einstein’s equations, whether

these were finite-age models or not. However, with the discovery of the cosmic

microwave background in 1965 the balance tipped decisively to the advantage of the

big bang. According to this theory, in the very early and hot universe light (or

photons) would be coupled to elementary particles and unable to escape them. But

when the universe cooled enough for protons and electrons to form hydrogen atoms

the universe became transparent – filled with freely moving photons. This

“background radiation” originating more than 13 billion years ago still exists in the

28 See H. Kragh, Cosmology and Controversy: The Historical Development of Two Theories of the

Universe (Princeton: Princeton University Press, 1996). 29 M. Bunge, “Cosmology and magic,” The Monist 47 (1962), 116-141. 30 Fred Hoyle, The Nature of the Universe (New York: Harper & Brothers, 1950), p. 124. On the

origin and history of the term “big bang,” see H. Kragh, “Naming the big bang,” Historical

Studies in the Natural Sciences 44 (2014), 3-36. 31 F. Hoyle, “The universe: Past and present reflections,” Annual Review of Astronomy and

Astrophysics 20 (1982), 1-35, p. 23.

18

form of very weak microwaves. The existence of a background radiation thus follows

naturally from the big bang theory and had in fact been predicted on this basis by

Alpher and Herman as early as 1948. On the other hand, the new phenomenon could

be accommodated by the steady state theory only by means of arbitrary and highly

artificial hypotheses.

To make a long story short, by the late 1960s the steady state theory was

practically dead and the big bang alternative accepted by the majority of physicists

and astronomers. Today a much-refined version of Gamow’s hot big bang cosmology

has the status of a paradigm. As regards the name “big bang” some leading

cosmologists have suggested that it is a misnomer. This is not only because it alludes

to a noisy explosion localized in space but also because the big bang, if taken to be a

creation event at t = 0, is outside the standard models of physics and cosmology.32

Hoyle remained throughout his life a sharp critic of the victorious big bang

theory. Not only did he find it methodologically objectionable, he also argued that an

explosive beginning in a very simple object failed to account for the evolution of

order and structure in the universe. Here is how he phrased his objection in an

address of 1993, realizing that his opposition to the big bang theory was shared by

only a small minority of his colleagues:

Explosions do not usually lead to a well-ordered situation. An explosion in a junk-yard

does not lead to sundry bits of metal being assembled into useful working machines.

Yet after expanding for about a billion years something of this nature is supposed to

have happened to the universe. Galaxies formed that are widely similar over large

volumes of space. Stars formed. Life originated and evolved. Man arose and began to

think about it all. How such a structured world came into being remains unexplained.33

According to modern big bang cosmology there is no basis for Hoyle’s objection. On

the contrary, structures in the universe follow from the lack of homogeneity that the

theory predicts for its very early development.

5. Aspects of modern cosmology

The big bang standard theory has since its establishment some fifty years ago been

greatly developed theoretically as well as observationally. The best cosmological

32 P. James E. Peebles, Principles of Physical Cosmology (Princeton: Princeton University Press,

1993), p. 6. 33 Hoyle, Origin of the Universe (ref. 1), p. 18.

19

measurements combined with the best theoretical model results today in an age of

the universe of remarkable accuracy, namely 13.799 0.021 billion years. Some of the

advances relate to the very early universe and even to the ultimate question of its

origin. Did the universe originate in an extended object of some kind, perhaps a

modern analogue of Lemaître’s primeval atom, or in a singularity of zero extension?

If the latter is the case it is tempting to identify the initial singularity with the

absolute beginning of the universe. Since the singularity has no physical properties

whatsoever, the question of where it came from need not arise.

In work around 1965 Roger Penrose, Stephen Hawking and a few other

mathematical physicists proved that a universe governed by the general theory of

relativity must necessarily possess a space-time singularity. Although the proof is

sometimes taken to imply that the universe started in a singularity, this is too strong

an interpretation. Almost all cosmological models describe a finitely old universe but

not, when physics is added to the mathematics, a universe starting in a singularity.

The Penrose-Hawking singularity theorem builds solely on general relativity and

thus does not take quantum effects into regard. But it is generally believed that the

physics of the very early universe can be understood only on the basis of a unified

theory of gravitation and quantum mechanics. This era of quantum gravity is

believed to be the inconceivably small time interval between t = 0 and t = 10-43 sec,

where the latter is known as the Planck time. As far as physics is concerned, the

initial singularity is not inevitable.

In modern early-universe cosmology the vacuum is a main player. From the

point of view of quantum mechanics the vacuum is entirely different from the void

or nothingness of classical physics (or perhaps one should say metaphysics). A

vacuum is necessarily filled with energy which fluctuates wildly and spontaneously.

Might the universe have its origin in a quantum fluctuation? This is what the

American physicist Edward Tryon proposed in 1973, thus giving a new twist to the

concept of creatio ex nihilo. Although Tryon’s model turned out to be flawed, other

physicists came up with similar suggestions of “Creation of Universes from

Nothing,” as the title of a 1982 paper reads.34 The author, the Russian-American

34 E. Tryon, “Is the universe a vacuum fluctuation?” Nature 246 (1973), 396-397; Alexander

Vilenkin, “Creation of universes from nothing,” Physics Letters 117 B (1982), 25-28. See also

Alexei Starobinsky, “Future and origin of our universe: Modern view,” pp. 71-84 in V.

Burdyusha and G. Khozin, eds., The Future of the Universe and the Future of Our Civilization

(Singapore: World Scientific, 2000).

20

physicist Alexander Vilenkin, claimed that his theory explained how “the universe is

spontaneously created from literally nothing.” However, this and other theories in the

same tradition do not really explain the creation of the universe ex nihilo since they

merely push back the creation scenario to a hypothetical vacuum scenario. They

presuppose a primordial quantum vacuum, which is an object describable by the

laws of physics and in no way the same as “nothing.” Where did the quantum

vacuum come from?

At the time Vilenkin wrote his paper the picture of the very early universe

had undergone a revolution in the form of the so-called inflation theory. To put it

briefly, according to this theory there was an extremely brief phase in the history of

the very early universe, shortly after the Planck time, in which empty space expanded

at a stupendous speed. Although the inflation lasted from only 10-36 sec to about 10-33

sec after t = 0, during this brief interval of time space expanded by a factor of 1030 or

more. The basic mechanism responsible for the huge expansion is believed to be a

hypothetical “inflaton field” which can be represented by a quantum version of the

cosmological constant appearing in Einstein’s equations. This constant has the

remarkable property that it leads to a negative pressure and an associated vacuum

energy density (rather than the energy itself) which remains constant. It follows that

the inflation generates an enormous amount of energy – almost out of nothing. After

the brief inflationary phase, the much slower normal expansion of the now very hot

and energy-rich space takes over.

It all sounds very exotic, almost incredible, but most cosmologists consider

the inflation scenario, in one of its many versions, to be convincing because of its

explanatory and predictive power. They believe that we know what the universe

looked like just 1035 sec after t = 0. This is most interesting but cynics will argue that it

does not bring us nearer to answering the question of the ultimate origin. Where did

the inflaton field come from?

The success of the inflation theory drew increased attention to the role of the

cosmological constant as a measure of the energy density of the vacuum. However, it

was not studies of the very early universe that confirmed Einstein’s cosmological

constant but astronomical observations of the present expansion rate. In the late

1990s it turned out that the universe is accelerating, meaning that it expands at an

increasing rate as if it is blown up by a self-repulsive “dark energy.” The precise

nature of this dark energy is still unknown but the consensus view is that it is a

manifestation of the vacuum energy associated with the cosmological constant. This

21

strange kind of energy actually dominates the present universe, as it makes up

roughly two-thirds of all energy and matter in the universe and in the future will

dominate even more. While the discovery of dark energy has great consequences for

the far future of the universe it is not equally relevant for the very early universe. On

the other hand, it underlines the importance of the vacuum energy density as a

fundamental characteristic of our universe.

The original inflation theory was soon developed into versions of “eternal

inflation” primarily by Vilenkin and Andrei Linde, who suggested that in the

universe as a whole, new inflating regions will be produced more rapidly than non-

inflating regions. Inflation is self-generating, if not in our observed universe then in

the much bigger and presumably infinite universe at large. According to Linde, “the

universe is an eternally existing, self-reproducing entity that is divided into many

mini-universes much larger than our observable portion, and … the laws of low-

energy physics and even the dimensionality of space-time may be different in each of

these mini-universes.”35

Here we have the controversial and much-discussed hypothesis of the so-

called multiverse, the idea that there exists a multitude of other universes each with

its own vacuum energy density.36 We also have the no less controversial idea that,

despite the big bang origin of our universe, the universe at large is infinite in its

temporal extension. According to some proponents of eternal inflation the infinity

covers the past as well as the future, meaning that there is no proper origin. Other

proponents argue that although inflation will go on forever in the future, it is

probably not eternal in the past. In that case a primary big bang is still part of the

picture.

As several modern cosmologists have noted, the classical and by now

defunct steady state theory of Hoyle and his colleagues can in some respects be seen

as a precursor of eternal inflation, but only if the latter theory can be extended

eternally to the past. For those who think that it can, Hoyle’s motivation is still valid.

In a paper advocating eternal inflation in the past two physicists say about the steady

35 A. Linde, Inflation and Quantum Cosmology (Boston: Academic Press, 1990), p. 29. 36 The multiverse hypothesis exists in several versions. According to some of them the many

other universes are causally separate, meaning that they are unobservable even in principle.

For an account of the multiverse and its history ca. 1990-2010, see H. Kragh, Higher

Speculations: Grand Theories and Failed revolutions in Physics and Cosmology (Oxford: Oxford

University Press, 2011), pp. 291-324.

22

state theory that it is “appealing because it avoids an initial singularity [and] has no

beginning in time.”37

6. Did the universe have a beginning?

Eternal inflation is one way of avoiding what some physicists consider unpalatable,

namely an absolute origin of the universe, but there are several other ways. One of

them is to introduce a new measure of time that conjures an infinite past out of the

finite one. This can be done by replacing the ordinary time parameter t by a new one

θ which is logarithmically related to t time. On the new concept of time the big bang

did not occur at t = 0 but at θ = − ∞ (minus infinity), which means that it never began.

In the words of a French physicist, “the numerical finiteness of the age of the

universe by no means precludes its conceptual infiniteness.” There is a sense in

which “the universe is infinitely old and had no definite beginning.”38 In this sense

the big bang can be approached asymptotically but never reached, somewhat in

analogy to the concept of zero absolute temperature (see Section 7). Conceptually

appealing as the idea may seem, most physicists consider it nothing but a formal

trick. They maintain that there was an original big bang approximately 14 billion

years ago.

In philosophical and mythological contexts the idea of a cyclic or oscillating

universe can be found in ancient Greek and Indian cosmologies. The general idea is

that our present universe is the outcome of a previous one and that it will itself result

in a successor universe; and, moreover, that there is an endless number of these

earlier and later universes. If so there would be neither a beginning nor an end to the

universe as a whole. In more or less scientific versions ever-cyclic models attracted

much interest during the nineteenth century, sometimes in the form of the eternally

recurrent universe in which the cycles were identical in every detail and every single

event in history thus endlessly repeats itself. For example, the famous German

philosopher Friedrich Nietzsche advocated such a world view.39

37 Anthony Aguirre and Steven Gratton, “Steady-state eternal inflation,” Physical Review D 65

(2002), 083507. 38 Jean-Marc Lévy-Leblond, “Did the big bang begin?” American Journal of Physics 58 (1989),

156-159. The idea of two time scales goes back to the 1930s, when it was first discussed by the

British cosmologist Edward Arthur Milne, who distinguished between what he called

kinematic and dynamic time. 39 Robin Small, Nietzsche in Context (Aldershot: Ashgate, 2001).

23

In the context of relativistic cosmology cyclic models were reconsidered by

Friedmann in his pioneering paper of 1922. In this context the expansion of the

universe is followed by a contracting phase which again is followed by an expanding

phase, and so on. The bounce from contraction to expansion – or from a big crunch to

a big bang – is supposed to take place smoothly between two non-singular states of

high but not infinitely high density and temperature. Many models of this kind have

been proposed but they all suffer from severe difficulties and especially so if they

suppose an infinite number of earlier universes40. If there can only be a finite number

of previous cycles the whole idea loses much of its philosophical appeal, for then

there must be a first cycle and the questions of its origin reappears. The classical

cyclic universe only makes sense if space is closed and expanding at a decreasing

rate. With the discovery of the acceleration of space this turned out to be wrong and

models of this kind were consequently abandoned.

Nonetheless, the appeal of an endless universe with no beginning was too

strong to be given up completely. In a new cyclic model proposed in 2002, Paul

Steinhardt and Neil Turok developed a cosmology with an eternal sequence of

identical cycles consisting of expansions and contractions. Contrary to earlier models

it relied on an open and accelerating universe in agreement with observations and it

was specifically constructed as an alternative to the inflation scenario. In a popular

address Steinhardt summarized: “Space and time exist forever. The big bang is not

the origin of time. Rather, it is a bridge to a pre-existing contracting era. The universe

undergoes an endless sequence of cycles in which it contracts in a big crunch and re-

emerges in an expanding big bang, with trillions of years of evolution in between.”41

Although a few physicists continue developing the model, it has failed in making an

impact on mainstream cosmology. Yet it is worth mentioning as a modern example

of the enduring appeal of an eternal-cyclic universe in which the question of origin

does not arise.

Finally there is a class of cosmological models which include the hypothesis

of a pre-big bang universe but are not cyclic in the ordinary sense. One may speak of

bouncing rather than cyclic models. At about 1950 Gamow speculated that the

40 For the history of cyclic universe models, see Kragh, Higher Speculations (ref. 36), pp. 193-

216. 41 P. Steinhardt, “The endless universe: A brief introduction,” Proceedings of the American

Philosophical Society 148 (2004), 464-470. See also P. Steinhardt and N. Turok, Endless Universe:

Beyond the Big Bang (New York: Doubleday, 2007).

24

universe might have evolved from a previous state of nearly infinite rarefaction

which slowly had contracted gravitationally into a super-dense state; out of this state

the big bang of our present universe emerged. It was thus a temporally symmetric

picture of the universe, stretching from minus infinity to plus infinity and with no

absolute beginning. Modern theories founded on quantum gravity have resulted in

pictures which, from a qualitative point of view, share the basic features of Gamow’s

classical picture.

The best offer of a theory of quantum gravity may be the fundamental theory

of superstrings, a unified many-dimensional theory of gravity and the three forces of

nature which can be understood in terms of quantum mechanics. These are the well-

known electromagnetic force and the two short-range forces known as the weak and

the strong (or nuclear) interactions. It turns out that the electromagnetic and the

weak forces can be unified in a single theory and that this “electroweak” theory can

be extended to cover also the strong force in what is called “grand unified theory.”

String theory is even grander as it offers a unified formalism encompassing all the

four interactions. The prefix “super” indicates so-called supersymmetry with the

implication that all the known elementary particles having partner particles. For

example, the photon has a supersymmetric partner called a photino. Alas, none of

these superpartners have been detected in experiments. What is of relevance here is

that physicists have constructed cosmological models on the basis of string theory

and that these models avoid the initial singularity and the problem of an absolute

beginning.

According to string cosmology or what is sometimes called pre-big bang

cosmology, the big bang at t = 0 was not the origin of everything but a moment in

cosmic time when a state of very high but finite density bounced into a state of

rapidly decreasing density. Strings are irreducible one-dimensional objects and the

theory includes a fundamental length which can be thought of as the dimension of a

point in space; the length is about 10-34 m, which is also the smallest radius of cosmic

space. The string scenario posits a flat and nearly empty universe in the indefinite

past and also, symmetrically, in the indefinite future. From the eternally existing pre-

universe our universe emerged when the density reached the maximum value in a

big crunch, or what from our point of view was a big bang. After that followed an

inflationary phase and eventually the eternally accelerating universe as we observe it

today.

25

Although there is no definite origin of the string universe, one of its leading

advocates, the Italian physicist Maurizio Gasperini, believes that “the Universe was

born according to God’s will, with an act of creation having its ultimate and complete

purpose in human beings.”42 He recognizes that this is of course a personal view and

not one which can be justified scientifically. There was no origin of the universe, and

yet it was created. His view brings to mind the old discussion going back to Thomas

Aquinas of whether or not God could have created an eternal universe.

Apart from string theory, “loop quantum gravity” (LQG) is another

candidate for a unified theory of general relativity and quantum mechanics. LQG is

entirely different from string theory, for other reasons because it does not include

supersymmetry and operates with only the four known dimensions of space-time.

Despite the differences, when applied to the universe at large it results in a picture

which is surprisingly similar to the one of string cosmology.43 While strings cannot be

squeezed to zero volume, in LQG space itself is discrete, in a sense made up of

minimum “space atoms” of a volume of the order of 10-100 m3. For this reason loop

quantum cosmology reproduces the feature of string cosmology, that there is no big

bang singularity. The universe pictured by LQG theorists also has no beginning and

no end. It develops from a past-eternal pre-universe over the bounce at t = 0 to the

future-eternal present universe. In spite of the similarities between the cosmic

scenarios offered by the two theories of quantum gravity they result in different

predictions which can in principle (but perhaps only in principle) be tested by

measurements. Work in this or other traditions of quantum cosmology continues to

this day, suggesting that it is theoretically possible to explain the big bang at t = 0 as

the result of a previously contracting universe.44

It seems that modern theories of quantum gravity are no more able than

other cosmological theories to come up with a good answer concerning the ultimate

origin of the universe. Here is the view of Thanu Padmanabhan, an Indian

cosmologist and specialist in quantum gravity who has also investigated modern

steady state theories of the universe:

42 M. Gasperini, The Universe Before the Big Bang: Cosmology and String Theory (Berlin:

Springer, 2008), p. 195. 43 Martin Bojowald, “Follow the bouncing universe,” Scientific American 299 (April 2008), 44-

51. 44 Steffen Gielen and Neil Turok, “Perfect quantum cosmological bounce,” Physical Review

Letters 117 (2016), 021301.

26

How (and why!) was the universe created and what happened before the big bang?

The cosmologist giving the public lecture usually mumbles something about requiring

a quantum gravity model to circumvent the classical singularity – but we really have

no idea! String theory offers no insight; the implications of loop quantum gravity for

quantum cosmology has attracted fair amount of attention recently but it is fair to say

that we still do not know how (and why) the universe came into being.45

Proponents of pre-big bang cosmologies may respond that the universe never came

into being and thus there is no question to be answered.

7. Philosophical and theological perspectives

We live in a big bang universe, but unfortunately there is no consensus what the key

term “big bang” covers. Physicists and astronomers generally refer to the big bang as

a brief but crucial chapter in the history of the universe, say from t = 10-12 seconds (or

sometimes 10-35 seconds) to t = 104 seconds. In this sense the big bang can be

considered a scientific fact supported by a wealth of reliable evidence. But the term is

also used, especially but not only by philosophers, as a reference to the absolute

beginning at t = 0. This is quite a different meaning and the concept it covers can in

no way be characterized as scientifically documented. Creation in an absolute and

therefore metaphysical sense is not part of what most astronomers and physicists

refer to as the big bang scenario any more than an absolute origin of life is part of

what most biologists refer to as the neo-Darwinian evolution scenario.

Terminological ambiguities apart, if there were an absolute origin at t = 0, a

cosmic creation event, can it be explained? The emergence of the first elementary

particles during the quark era some 10-9 seconds later can be explained from the

previous state of the universe, but what about the beginning of time itself? As

mentioned, an ordinary causal explanation based on an earlier state is out of the

question, at least if we disregard speculations of a multiverse or a pre-big bang

universe. As an alternative one might consider other forms of explanation not

ordinarily used in science, such as a teleological explanation where the origin of the

universe is associated with a purpose; or one may just renounce the possibility of

understanding the singular event. This event, the creation of the universe, concerns

45 T. Padmanabhan, “Understanding our universe: Current status and open issues,” pp. 175-

204 in A. Ashtekar, ed., 100 Years of Relativity. Space-Time Structure: Einstein and Beyond (New

Jersey: World Scientific, 2005), p. 199.

27

not only the origin of what constitutes the universe – space, time, energy, fields, and

matter – but also the origin of the laws that govern it. Scientific explanations are

nomological, meaning that they are based on laws of nature, but how did these laws

come into being? When cosmologists describe the early universe they make use of

relativity theory, quantum mechanics, thermodynamics and other theories. Why do

these laws of nature apply rather than some other laws that one might imagine?

It has been suggested that the singular big bang event is not something that

belongs to the ontology of cosmic evolution but that it can be approached only

asymptotically. Concepts of this kind are known from other areas of physics which

may serve as analogies. For example, the absolute zero of temperature (T = 0 K or

approximately − 273.15 °C) can be approached arbitrarily closely but never be

reached either in nature or in the laboratory. Like many analogies it serves a heuristic

purpose only. A decisive difference is that the temperature T = 0 is well defined and

can be understood in terms of physics. The cosmic t = 0 event, on the other hand, is

not comprehensible in the same way. It is tempting to consider this event in the light

of epistemology rather than ontology. In this case the singular big bang is not

something which once existed but an epistemic horizon, a limit for the intelligibility

of the cosmos. Science has always been faced with boundaries beyond which it

seemed powerless but which were nonetheless transgressed by the progress of

science. These boundaries or horizons move, and there is no reason why the Planck

time is an absolute horizon of knowledge. Yet it is possible that at least one

boundary, the one at t = 0, will never be removed.46

At the bottom of any discussion of the origin of the universe lies the difficult

concept of time. Instead of imagining a metaphysical state of nothingness out of

which the physical universe magically emerged, one may imagine a frozen proto-

universe in which there were no processes at all and hence also no possibility of

defining time. It may have been something of this kind that Lemaître had in mind

when he introduced the primeval atom in 1931. However, the imagery seems to be of

no help and is in any case beyond science. Time is relational. It presupposes an active

universe with processes that can function as clocks and the clocks of course belong to

the universe. According to Stephen Hawking, “To ask what happened before the

universe began is like asking for a point on Earth at 91 north latitude; it just is not

46 Willem B. Drees, Creation: From Nothing until Now (London: Routledge, 2002), pp. 13-15;

Milton K. Munitz, Cosmic Understanding: Philosophy and Science of the Universe (Princeton:

Princeton University Press, 1986), p. 172.

28

defined.”47 Literally speaking the big bang universe has always existed and will exist

forever irrespective of a future big crunch or not. The terms “always” and “forever”

are temporal terms meaning at all times and there was no time at which the universe

did not exist.48 The word “then” is also temporal and for this reason one cannot say

that “first there was nothing and then there was something.” Although the big bang

universe has always existed it is not past eternal like the steady state universe.

It should be kept in mind that time as used by cosmologists is basically a

mathematical parameter appearing in the field equations. The time parameter t is

positive and varies continuously, meaning that it can attain any value however small.

In principle it can be immensely smaller than the Planck time 10-43 seconds. Why not

10-1000 seconds? The way that specialists in early-universe cosmology speak about

time is not only abstract but also in many ways remote from the usual concept where

time is a measure associated with real physical processes. It is generally believed that

the cosmic time scale must have a physical basis in the form of a clock and not be just

a mathematical symbol. The problem is that there are no known processes varying

with a period so small as the Planck time or the time scale of the inflation era. The

smallest decay time known from particle physics is about 10-24 seconds, trillions of

times larger than the Planck time. It is far from clear if the time concept used in this

branch of cosmology is well defined or is the same concept of time as used elsewhere

in science.49 And it is even less clear if the physical concept of time can be

meaningfully extended to the pre-big bang universe hypothesized by some theories

of quantum gravity.

The question of the origin of the universe continues to be of theological

interest and perhaps even more so than of scientific interest.50 On the face of it the big

bang theory with its cosmic origin of time seems to offer support for a theistic

interpretation. After all, if the origin at t = 0 is beyond scientific comprehension and

the universe is nonetheless of finite age, doesn’t it confirm the view of traditional

47 S. Hawking, “Quantum cosmology,” pp. 631-651 in S. Hawking and W. Israel, eds., 300

Years of Gravitation (Cambridge: Cambridge University Press, 1987), p. 651. 48 Jesús Mosterin, “Philosophy and cosmology,” pp. 57-88 in G. Munévar, ed., Spanish Studies

in the Philosophy of Science (Dordrecht: Kluwer Academic, 1996), p. 64. 49 Svend E. Rugh and Henrik Zinkernagel, “On the physical basis of cosmic time,” Studies in

History and Philosophy of Modern Physics 40 (2009), 1-19. 50 The literature on the subject is considerable. For a concise introduction, see Hans

Halvorson and Helge Kragh, ”Theism and physical cosmology,” pp. 241-255 in Charles

Taliaferro, ed., The Routledge Companion to Theism (London: Routledge, 2013).

29

theism that God, a necessary being, created the universe out of nothing? Although

the success of the big bang model does not really confirm theism, this is what many

believers have argued. Notably, in an address of 1951 the pope, Pius XII, endorsed

the new big bang theory as scientific proof of the biblical creation story.51

“Everything seems to indicate that the material content of the universe had a mighty

beginning in time,” the pope asserted. He continued:

Thus, with that concreteness which is characteristic of physical proofs, it [modern

science] has confirmed the contingency of the universe and also the well-founded

deduction as to the epoch when the world came forth from the hands of the Creator.

Hence, creation took place. We say: therefore, there is a Creator. Therefore, God exists!

The papal argument presupposes cosmic creation ex nihilo to be miraculous and yet

at the same time it derives creation from a scientific theory based on the laws of

nature. The theist cannot have it both ways. God transcends the laws of nature,

which he created together with the universe, and the laws cannot act as a guide to

how he created the universe.

The question of the relationship between big bang cosmology and divine

creation has been discussed endlessly but without much coming out of the

discussion.52 Just as the finite-age big bang universe offers no strong support for

theism, so an infinitely old universe offers no strong support for atheism. The

American astronomer Carl Sagan evidently thought that an eternal universe is

incompatible with theism. Imagine that the pre-big bang model or some other past-

eternal model was proved correct. This, Sagan suggested, would be “the one

conceivable finding of science that could disprove a Creator – because an infinitely

old universe would never have been created.”53 However, to counter the argument

the theist only has to appeal to the concept of continual creation discussed in the

middle ages. Irrespective of its age there needs to be a cause that maintains the

existence of the universe and this cause qualifies as a creation.

51 The papal address can be found in P. J. McLaughlin, The Church and Modern Science (New

York: Philosophical Library, 1957), pp. 137-147, and online as

http://www.papalencyclicals.net (accessed 10/08/2016). 52 See, for example, William L. Craig and Quentin Smith, Theism, Atheism and Big Bang

Cosmology (Oxford: Clarendon Press, 1995). 53 C. Sagan, The Demon-Haunted World: Science as a Candidate in the Dark (London: Headline,

1997), p. 265.

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Indeed, most theologians and Christian philosophers agree that creatio

continua is more important than the original form of creation corresponding to a

finite-age universe. As early as 1933 the British mathematician and bishop of

Birmingham, Ernest William Barnes, pointed out that his God was not to be found in

the origin of our universe:

Men have thought to find God at the special creation of their own species, or active

when mind or life first appeared on the earth. They have made him God of the gaps in

human knowledge. To me the God of the trigger is as little satisfying as the God of the

gaps. It is because throughout the physical Universe I find thought and plan and

power that behind it I see God as creator.54

During the controversy over steady state cosmology in the 1950s this theory, with its

infinite time scale in both directions, was sometimes considered a challenge to

theism. But as theologians were quick to point out, the claimed problem was nothing

but a pseudo-problem; the question of whether the universe has a beginning or not,

is of no real importance for theology. A later theologian expressed it in this way:

“Divine creativity is not restricted to a finite stretch of time, or to the past, but is a

continuing activity, as theologians from Augustine to Luther and Calvin to the

present have argued. Creation is not just a matter of beginnings.”55 It is debatable

whether this kind of response is satisfactory. Continual creation in the theological

sense is metaphysical and without a counterpart in physical cosmology. Sceptics will

argue that the appeal to creatio continua is nothing but a way of protecting the

Christian creation doctrine from scientific criticism. If divine creation is simply based

on the undeniable existence of the world it is impossible to argue against the

doctrine.

There is no agreement between theologians, or between theologians and

cosmologists, regarding the relationship between Christian belief and cosmological

models. Most theologians deny a direct relation, such that the finite-age big bang

universe lends support to the hypothesis of a divine creator or that an eternal

universe disproves the hypothesis. But not all do. The Christian philosopher William

54 E. W. Barnes, Scientific Theory and Religion (Cambridge: Cambridge University Press, 1933),

p. 409. 55 Hyers, The Meaning of Creation (ref. 13), p. 67. For the response to the steady state theory,

see Erich L. Mascall, Christian Theology and Natural Science (London: Longmans, Green and

Co., 1956).

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Craig sides with Pius XII when he claims that “the big bang model thus provided

dramatic empirical verification of the biblical doctrine of creatio ex nihilo.”56

The question has been discussed for more than thousand years and one

might perhaps expect that the recent progress in physical cosmology would have led

to some clarification or even definite answers. But this has not been the case and it is

unlikely that it will ever happen. Science is impotent with respect to theological

doctrines and theology is of no direct relevance to science. Let me end this essay by

quoting the balanced view from an introductory textbook in astronomy:

If we use God as an explanation for the big bang, there would be no reason to look

further for a natural explanation. Use of supernatural explanations would shut down

science. … If science relied on a creator to explain the inexplicable, there would be

nowhere to go, no way to prove that explanation wrong. The question would have

already been settled. … Science does not deny the existence of God. God is simply

outside its realm.57

56 W. Craig, “Theism and physical cosmology,” pp. 419-425 in Philip L. Quinn and Charles

Taliaferro, eds., A Companion to Philosophy of Religion (Malden, MA: Blackwell Publishing,

1999). 57 Karl F. Kuhn, In Quest of the Universe (Boston: Jones and Bartlett Publications, 1998), p. 557.